Super Absorbent Polymer

Abstract

The present disclosure relates to a super absorbent polymer exhibiting an improved absorption rate and improved absorption performance.

1 . A super absorbent polymer that is a polyacrylic acid or salt thereof-based super absorbent polymer,
 wherein for all particles, an average value of circularity, which is calculated according to Expression 1 below, is approximately 0.90 or less,   an average value of CE diameters is approximately 220 μm to approximately 400 μm, and   a water retention capacity (CRC), which is measured according to EDANA method WSP 241.3, is approximately 33 g/g or more:
   circularity=perimeter of circle equivalent ( CE ) particle/perimeter of actual particle  <Expression 1>
 
   in Expression 1 above,   the perimeter of the CE particle means a perimeter length of a circle that has the same area as a two-dimensional image of a three-dimensional particle to be measured, and   the perimeter of the actual particle means a perimeter length of the two-dimensional image of the three-dimensional particle to be measured.   
     
     
         2 . The super absorbent polymer according to  claim 1 , wherein for all the particles, the average value of the circularity is approximately 0.70 to approximately 0.90. 
     
     
         3 . The super absorbent polymer according to  claim 1 , wherein an average value of an aspect ratio (A/R), which means a ratio of a shortest diameter of a particle to a longest diameter of the particle, is approximately 0.70 or more. 
     
     
         4 . The super absorbent polymer according to  claim 1 , wherein for all the particles, the average value of an aspect ratio (A/R), which means a ratio of a shortest diameter of a particle to a longest diameter of the particle, is approximately 0.70 to approximately 0.85. 
     
     
         5 . The super absorbent polymer according to  claim 1 ,
 wherein for all particles, an average value of high sensitivity (HS) circularity, which is calculated according to Expression 2 below, is approximately 0.80 or less:
     HS  circularity=(perimeter of  CE  particle) 2 /(perimeter of actual particle) 2 .  <Expression 2>
 
   
     
     
         6 . The super absorbent polymer according to  claim 4 , wherein for all the particles, the average value of the HS circularity is approximately 0.50 to approximately 0.80. 
     
     
         7 . The super absorbent polymer according to  claim 1 , wherein a ratio of a circularity of particles having a particle diameter of approximately 300 μm to approximately 600 μm to a circularity of all the particles of the super absorbent polymer is approximately 0.9 to approximately 1.1. 
     
     
         8 . The super absorbent polymer according to  claim 1 , wherein a super absorbent polymer has an absorbency under pressure (AUP), which is measured at 2.07 kPa (0.3 psi) according to EDANA method WSP 242.3, is approximately 25 g/g or more. 
     
     
         9 . The super absorbent polymer according to  claim 1 ,
 wherein the super absorbent polymer has an effective absorption capacity (EFFC) of approximately 30 g/g or more, where the effective absorption capacity (EFFC) is calculated according to Expression 3 below:
   effective absorption capacity (EFFC)={water retention capacity ( CRC )+absorbency under pressure ( AUP ) at 2.07 kPa (0.3  psi )}/2.  <Expression 3>
 
   
     
     
         10 . The super absorbent polymer according to  claim 1 , wherein a vortex time is approximately 40 seconds or less, where the vortex time is measured by a vortex measuring method at 24.0° C. 
     
     
         11 . The super absorbent polymer according to  claim 1 , wherein when 1 g of the super absorbent polymer is swollen with water having an electrical conductivity value of 110 μS/cm for 1 minute, a maximum capacity (free swell capacity) of water that is retainable in the super absorbent polymer is approximately 170 g or more. 
     
     
         12 . The super absorbent polymer according to  claim 1 , wherein a water retention capacity (CRC), which is measured according to EDANA method WSP 241.3, is from 35 g/g to 50 g/g. 
     
     
         13 . The super absorbent polymer according to  claim 1 , wherein an average value of CE diameters is approximately 230 μm to approximately 350 μm.